When bank notes are deposited at an ATM it is necessary to determine if the notes are legal or counterfeit. One process used in this determination is the taking of an image of each deposited note. This is achieved using a high resolution, at 100 dots per inch (DPI) or greater camera system. In addition it is now a legal requirement, of some licensing authorities such as the European Central Bank, to be able to trace each deposited note back to the customer who deposited the note.
As every bank note carries a serial number, printed in substantially the same place with standard sized characteristics, it would seem ideal to use the imaging technology within the ATM to trace the notes. Each note can then be referred to the user who deposited the note. However, notes can be deposited, as customers demand, at very high speeds (greater than 5 notes per second). At this speed the recognition engine comprising the high resolution camera operates at closer to 40 DPI. This resolution is sufficient to recognize the image of a note, but it is not good enough to read a serial number off of a note.
Therefore, it would appear that in order to utilize imaging to trace notes to a user very much more expensive higher resolution cameras and optics will be required.